The present invention relates to a self-locking safety belt device, especially for motor vehicles, comprising at least one vehicle-sensitive control system for the locking member, which in its locking position prevents further rotation of the belt reeling shaft, and further comprising a control device which, for the retracted belt, provides a release position for the control disc rotating with the belt reeling shaft, whereby the control disc is a component of the vehicle-sensitive control system, and, for a predetermined removal state of the belt, secures the control disc against further rotational movement and initiates the locking of the safety belt device. The control device comprises a first gear wheel connected to the reeling shaft and a second gear wheel, whereby both gear wheels have switching cams arranged thereat with which a switching lever for initiating locking of the control disc is movable.
A safety belt device of the aforementioned kind is known from European patent 0 535 551. In the known safety belt device a first gear wheel is arranged on the belt reeling shaft which, depending on the switching position, meshes with one of two further gear wheels positioned on a pivotable arm supported on the safety belt device. The three gear wheels have a respective switching cam whereby two of the switching cams in predetermined belt removal states will come into contact with one another. Further rotation of the belt reeling shaft with the resulting belt removal, respectively, a spring pulling action then causes pivoting of the pivot arm. The pivot arm in turn moves a spring arm, functioning as a switching lever and cooperating with the outer toothing of the control disc, between a release position and a locking position for the control disc. The securing of the control disc against further rotational movement relative to further rotation of the belt reeling shaft then causes deflection of the locking member and thus locking of the safety belt device. This embodiment of the safety belt device ensures that, upon reaching a predetermined removal length of the belt, the locking system of the belt device is always activated so that any further removal of belt results in locking of the safety belt device thus making further belt removal impossible, while belt retraction onto the safety belt device, i.e., reverse movement of the belt reeling shaft, will release the activation of the locking system when the corresponding switching position is surpassed.
The known safety belt device has the disadvantage that for realization of the disclosed control mechanism a plurality of components, such as pivot arm, gear wheels, movable switching lever, and a spring, are required whose manufacture and assembly are complicated and expensive. It is therefore an object of the present invention to simplify the control mechanism of a safety belt device with the aforementioned features.